1. Technical Field
Example embodiments of the present invention relate to a solution supplying unit and substrate treating apparatus having the solution supplying unit. More particularly, example embodiments of the present invention relate to a solution supplying unit capable of removing a photoresist and a substrate treating apparatus having the solution supplying unit.
2. Discussion of the Related Art
Generally, a semiconductor photolithography process includes a photoresist coating, an exposing, a developing, an etching and a removing of a photoresist. Using the photoresist as a mask, the exposing, the developing and the etching are performed, and then the photoresist is removed.
Generally, various kinds of solutions are used to remove the photoresist, and the solution is provided to a substrate through a solution supplying unit. For example, the solution may be a mixture of sulfuric acid and hydrogen peroxide, and the solution may be mixed in the solution supplying unit.
The sulfuric acid and the hydrogen peroxide are rotated in the solution supplying unit to use turbulence in mixing the sulfuric acid and the hydrogen peroxide. However, since specific gravities of the sulfuric acid and the hydrogen peroxide are different from each other, the sulfuric acid and the hydrogen peroxide are hard to be mixed. In addition, due to the specific gravity and a centrifugal force of the sulfuric acid, the hydrogen peroxide is hard to be provided into the solution supplying unit.
Even if the hydrogen peroxide is provided into the solution supplying unit, bubbles are generated due to boiling in mixing the sulfuric acid and the hydrogen peroxide. A pressure inside of the solution supplying unit increases due to the bubbles and thus the solution is flowed out. Then, the pressure inside of the solution supplying unit decreases. Thus, an amount of the out-flowed solution is not uniform. In addition, the bubbles are flowed out with the solution. Thus, the amount of the out-flowed solution is hard to be accurately controlled.